1. Field of the Invention
The present invention relates to a particulate trap system for an internal combustion engine which provides constant flow of exhaust gas to the burner, during regeneration.
2. Description of the Relevant Art
There are many particulate trap oxidizer configurations currently being developed for application to internal combustion engines and, more particularly, to diesel engines which have been criticized as having undesirable particulate emission levels. Systems which have been demonstrated as conceptually feasible generally utilize a burner, which is disposed upstream of a particulate trap, to heat the exhaust gas entering the trap to a temperature required to burn the particulates which have been accumulated on the trap during normal engine operation. These systems generally may require valve assemblies to divert, modulate, or restrict exhaust flow to the burner as well as air-fuel sub-systems to support efficient combustion within the particulate trap. The sub-systems are often required to monitor engine operating conditions such as speed and load in order to vary air-fuel mixtures according to changing exhaust gas flow and temperature, since control of temperature is critical for efficient regeneration and long filter life. As a result, large and complex burner and air fuel systems are often required, resulting in packaging and reliability concerns.